Field of the Invention
The present disclosure relates to a micro-needle, and more particularly, to a micro-needle and a micro-needle patch for transdermal delivery of active substances having pharmaceutical, medical, or cosmetic effects.
Description of the Related Art
For effective drug delivery of medicines for human body, a method of injecting a liquefied medicine via a hypodermic injection needle is widely used. However, a hypodermic injection needle having a diameter of several mm may stimulate a plurality of pain spots in a skin and induce pain to a patient, and a high skill-level is necessary to use the hypodermic injection needle.
Recently, to resolve the problems of a hypodermic injection needle, transdermal drug delivery methods using micro-needles having diameters and heights from dozens of μm to hundreds of μm are being actively researched. A micro-needle device simultaneously forms a large number of channels penetrating through an outer skin by using micro-needles for penetrating through the stratum corneum layer of a skin, which is a major barrier of transdermal drug delivery. A sufficient amount of a drug may be delivered to an epidermis layer or a dermis layer via the channels. Next, the drug are absorbed by blood vessels and lymph glands and is introduced into the circulation system of a human body.
In another example, the micro-needles are also used for cosmetic purposes. For example, a bioactive substance is applied onto a skin or micro-needles, and the bioactive substance is transdermally delivered by forming micro-channels in the skin by using the micro-needles.
Although the technique for transdermally delivering an effective substance by using the above-stated micro-needles is useful, patch-type micro-needles, which is a simplified form of a conventional micro-needle device having a complicated structure, is preferable. Furthermore, if micro-needles additionally contain a medically or cosmetically effective substance, it is necessary to secure process consistency with fabrication of micro-needles having fine structure and a mechanism for optimal application of effects and drug adjustment at a transdermal delivery.